Audio Flowers [last.fm] is the result of extensive research conducted at Last.fm into new techniques to measure structural change (or "complexity") in rhythm, harmony and timbre directly from MP3 files.
These three numerical measurements have been averaged to produce a single image, resembling the petals of a flower with the respective colors red, green and blue. The inner origin of the flower represents the average variability value of the shortest time scale (2 seconds), while the tips correspond to the variability values of the longest one (64 seconds).
The aim of these little summary visualizations is to allow people to get a better overview of the complexity of individual music tracks. Currently, the audio of about 17,000 tracks have been analyzed and visualized in this way. However, to assure they are on the right track, the developers are requesting volunteers to compare pairs of music tracks to check the accuracy of these flower depictions with the actual human perception.